A network is a path through which several apparatuses can transmit and receive information therebetween.
Apparatuses constituting the network may be called various names, such as servers, clients, routers, and switches, depending on functions and positions, but the apparatuses constituting a network are commonly called nodes.
Further, in a network, an apparatus to transmit information, that is, data, may be called a source, and an apparatus to finally receive data may be called a destination.
In the meantime, a configuration of the network becomes more complex with development of electrical/electronic devices and networks. Accordingly, in order to transmit data from a source to a destination, there may be a case in which data is directly transmitted from a source to a destination, but data is mostly transmitted through various paths, that is, many apparatuses existing in a network.
Accordingly, in order to transmit data from a source to a destination, that is, to perform communication, it is very significant to recognize the shortest path or an optimum path.
In general, the shortest path may be discriminated from the optimum path, that is, the shortest path refers to a path having relatively the shortest distance for transmitting data from a source to a destination, and the optimum path refers to a relatively more efficient path considering other factors, such as data transmission expenses, as well as a distance, for transmitting data from a source to a destination, but the present specification will collectively use a term the optimum path without the aforementioned discrimination.
In the meantime, such an optimum path is set by measuring a distance between nodes and determining nodes between a source and a destination based on the measured distance.
A distance between nodes in a network is not a physical and geographical distance between nodes in which nodes are actually located, but is a relative concept according to a rate of data transmission between nodes.
For example, when it is assumed that node 1 is an apparatus located in Seoul, node 2 is an apparatus located in New York, and node 3 is an apparatus located in Tokyo, node 1 is physically and geographically close to node 3, but an actual time for communication between node 1 and node 2 may be shorter than that for communication between node 1 and node 3 according to a state of a network, for example, a type of communication line and performance or a type of corresponding apparatus, and in this case, it may be expressed that a distance between node 1 and node 2 is shorter than that between node 1 and node.
In the meantime, various methods for measuring a distance between nodes capable of reflecting a characteristic of a network in a network having a configuration which becomes increasingly complex have been suggested, but a distance between nodes has failed to be effectively measured because a configuration of a network becomes increasingly complex.
Accordingly, a method and an apparatus capable of more effectively measuring a distance between nodes have been demanded.